USER MANUAL

After launching the application, select one of the following tab:
OpenGL
Extensions
Display Modes
Pixel Format
Report
Test
Database
Credits

OpenGL
Display system information and core feature test.

Extensions
Display extensions, sorted by vendor. If you have an Internet connection, you can retrieve from OpenGL.org the extensions's specifications that explain the available extensions. You can click on extension and press 'Search' for getting extension's specification from severals different databases. You can also use the left button mouse.

Display Modes
Display all supported display modes.

Pixel Formats
Display all supported pixel format
Report
Create a report based from current configuration.

Report
The OpenGL diagnostic tool performs some OpenGL initialisation and graphical test. It will use the desktop resolution. So in case of slow downs or initialisation errors, use a smaller desktop resolution. 

OpenGL 1.1 : use the standard OpenGL without extension usage.
OpenGL 1.2 : OpenGL test using GL_lock_array and glDrawElement.
OpenGL 1.3 : OpenGL using GL_lock_array and multitexturing.
OpenGL 1.4 : OpenGL test using GL_lock_array and multitexturing using a DOT3 shading and an ARB vertex program code.
OpenGL 1.5 : OpenGL test using Vertex Buffer Object.
OpenGL 2.0 : OpenGL test using a GLSL 1.0 program.
OpenGL 2.1 : OpenGL test using pixel buffer object.
OpenGL 3.0 : OpenGL test using OpenGL 3.0 Forward Context (only supported under Windows). 
Credits 
 execom / main code.
arekkusu / cocoa code.
genevois / web site / graphist.

Links
Here a list of useful links, related to OpenGL Extensions and Programming:
Apple' s OpenGL Extensions Guide
OpenGL® Extension Registry
Delphi3D PC OpenGL Hardware Registry
Understanding and Detecting OpenGL Functionality
MacOS X OpenGL information

OpenGL EXTENSIONS

A very extensive list of details of all extensions available of your system, which OpenGL functions are implemented and more.
A core feature set check also show how well from OpenGL version 1.2 to 4.0 are implemented in your system.
More than 450 extensions reported and collected since 2000!

OpenGL Extensions Viewer has been suggested by OpenGL.org
in the OpenGL technical FAQ (see 23.050) (**)
and by nVidia as Developer Resources.

Vulkan Extensions are available in the Vulkan Report Section

RENDERER DATABASE

A database of all known renderers for Windows and MacOSX is available. If an renderer is being updated, you can submit to the server. You can also update to the latest database directly from the application.

FAQ

Q> I'm using a software that requires OpenGL 2.1, but I'm not able to find the driver to load
A> You can't really download OpenGL but only download display drivers that have OpenGL. Check with OpenGL Extensions Viewer what version it shows. If it reporting 'GDI Renderer', it means that something is blocking OpenGL from working. Sometimes an environement variable with QT_OPENGL solves the problem. 

Q> I want to run Blend on my computer. It requires OpenGL 3.3 or above. OpenGL Extensions Viewer is reporting '4.613572 Core Profile Compability 19.11.1'. Will this version works ?
A> Yes it will works, the version is the first figures in the version name, in this case it is 4.6

Q> I've downloaded the latest version of OpenGL, because it was necessary to play a certain game. This game requires OpenGL 2.1 or above. but once I open, it says it is version 1.1
A> As said, it means something is blocking OpenGL to works. For example, opening an OpenGL software thru a remote distance, or virtual machine doesn't works most of the time. Check with OpenGL Extensions Viewer to see which version is installed, especially the DirectX version. If you have DirectX 11, there is good chance that OpenGL is compatible but a software, or resolution is blocking it.